Braking system



Mmmm wy GQV. MORRIS 2,@3694@ BRAKING SYSTEM Filed Deo. 11, 1955 f 3 sheets-sheet 2' 131 138 155 DC 182m@ 127 l Si 187 1H mm m 185 89 191 JLUNNING v Dc B5 134v EMERGENCY 16 RELAY VALVE UMING T19 177 176 Mmm/0m MAIN Rmvom Bnventor attorneys RAE@ AWM m ww.

G. v v MORRIS BRAKING SYSTEM 5 Sheets-Sheet Filed DGO. 1l,- 1955 :inventor Patented Apr. 7, 1936 aigre PATENT BRAKING SYSTEM George V. Morris, Eugene, Oreg., assignor to The New York Alr Brake Company, a corporation of New Jersey Application December 1l, 1933, Serial No. 701,913

47 Claims.

This invention relates to braking systems and particularly to systems involving electrical control features. The electrical control features are of general application, and, since their greatest 5 use will probably be found in connection with systems of the electro-pneumatic type, the invention will be described as embodied in or as supplementing a pneumatic system of known form, but without intention to limit it to this particular'system or to systems of the same general type. Such novel pneumatic features as are involved relate chiefly to the translation of brief electrical impulses utilized in this control system, into more sustained pneumatic functions.

The pneumatic side of electro-pneumatic brakes has already been highly developed, and systems, quite diverse in their pneumatic aspects, have been proposed. Some of them are in commercial use. Their chief limitations arise from problems of permissible voltage, line losses and waste of electrical energy, and these limitations are such that use in trains longer than say about twenty calrs, is generally consideredy impracticable. Nearly all such systems involve the use of magnet valves or solenoid valves. Closed circuit (normally energized) operation is essential from the safety standpoint. Parallel connection of the units on the various cars is usually adopted to avoid the resistance variations inherent in series connection on trains of varying length.

The present system, being of the closed circuit, parallel connection type, is available for use in most of the prior art electro-pneumatic systems in lieu of the more conventional electrical circuits used heretofore. In some cases translating means to interpret brief impulses might be necessary, as in the quick service venting mechanism hereinafter illustrated. Furthermore new improved pneumatic systems can be devised to take advantage of the superior characteristics of the electrical circuits here disclosed.

The selection of any particular pneumatic system to illustrate the present invention is thus a matter of wide choice. In the present case the selection has been governed by the following practical considerations. Since the invention exhibits the greatest advantage on long trains, and since the K type freight triple, long standard on American railways, is used on the longest trains, the invention is shown applied to this type of triple valve in conjunction with conventional locomotive controlling equipment, only slightly modified.

Thus a highly' practical eld of application is opened, but without implying limitation to that field.

Generally considered, the invention involves two main circuits, each with means (condensers) for storing electrical energy on each car. On each car an asymmetric resistance device protects the actuated device (magnet valve) against response during charging of the storing device, and ensures its immediate response to discharge of the storing device. These two main circuits provide for two functions, preferably emergency application (by brake pipe venting) and service by quick service venting. The third function (preferably release) is controlled by disturbing the relative voltage of the two main circuits. These circuits are normally balanced and when thrown out of balance, by raising the voltage of one, cause discharge of a special release condenser. This discharge causes the release magnet to respond. After such response the cross flow between the two main circuits is sufficient to retain the release magnet armature in shifted position.

This is a desirable arrangement because the two application circuits are normally closed, while the release magnet winding is normally inert. This is relatively unimportant if the electrical release valve is merely a retainer, but in systems in which it is a true release valve, as is the case in some electro-pneumatic systems, the feature is very important because failure of the circuits cannot cause the release valve to open and defeat an application.

The advantage in using condensers arises from the fact that with proper circuit constants on each car, the effects of line losses can be overcome, so that the condenser on the last car even in a train of say two hundred cars, will charge practically to the voltage at the terminals of the generators on the locomotive. This per mits the use of safe voltages, with conductors of reasonable size, and with jumpers of reasonably simple constructions between cars. Furthermore, the total current flowing after the system is charged is small, the leakage current of a well designed commercial condenser being low.

For supervisory purposes a third circuit may be used and if used gives a continuous indication of the condition of the circuits. It may also be used as a telephone circuit.

An embodiment of the invention as applied with H-type engineers brake valve and K-type triple valves (both standard on American railways) will now be described with reference to the accompanying drawings:

Fig. l is a diagram of the circuits for a train comprising a locomotive, one freight car and a caboose. No brake circuits are shown on the caboose, but the leads therefor are shown. The brake equipment would be merely a duplicate of that shown for the freight car.

Fig. 2 is a view showing an engineers brake valve and related apparatus chiey in section, and illustrating the connection of this apparatus with the circuits diagrammed in Fig. l. The illustration of the brake Valve is conventional to the extent that the ports are illustrated as if they all lay in a single plane. The valve is in running position.

Fig. 3 is a view similar to a portion of Fig. 2 and showing the rotary valve is release position.

Fig. 4 is a similar view showing electric holding position.

Fig. 5 is a similar view showing service position.

Fig. 6 is a similar view showing lap position.

Fig. 7 is a similar View showing emergency position.

Fig. 8 is a vertical axial section of a K-type triple valve in release position and equipped with a modified front cap, and associated with a special ller piece, the front cap carrying the emergency magnet apparatus, and the filler piece the service magnet apparatus and the release (retainer) magnet apparatus.

Fig. 9 is a fragmentary View, similar to a portion of Fig. 8, showing the quick service vent slide valve in veriting position.

Referring rst to Fig. 8, 11 represents the body and I2 the lower case of a K-type triple valve. The parts in the body and lower case are all standard and need only be identified, as follows:-slide valve bushing I3, cylinder bushing I4 with charging groove I 5, triple piston I3 with stem I'I, retard stop I8, retard spring I9, slide valve 2| actuated by stem I'I with lost motion, graduating valve 22 positively shifted by stem I1, emergency cylinder bushing 23, emergency piston 24, piston guiding spider 25, emergency check 26, brake pipe check Z'I and check valve spring 28. The porting is conventional. In the slide valve seat are brake pipe quick service port 29, brake cylinder quick service port 3l, exhaust port 32 (leading to exhaust connection 33), brake cylinder port 34, emergency port 35. In the slide valve are two quick service ports 35, 31, exhaust port 88 with the usual restricted extension effective in retarded release position, service port 39 controlled by the graduating valve 22 and emergency port 4I. In the graduating valve 22 is quick service cavity 42 which at times connects ports 36 and 31.

The brake pipe 43 is connected to the lower case I2, as usual, and communicates with a passage 44, which in the usual K valve leads directly to the space to the left of piston I l5. In the present case a special front cap 45 is used, having a passage 45 leading to the upper seat 4l of double beat valve 48. The valve 48 is in chamber 49 which communicates by passage 5I with the space to the left of piston I5. The valve 48 also coacts with a lower seat 52 to open and close an atmospheric vent port leading from chamber 49. The double beat valve 48 is shifted between seats 4'1 and 52 by the energization and deenergization of a winding 53. Normal condition is with winding 53 deenergized and valve 48 closing on seat 52. Excitation of winding 53 occurs in emergency, and shifts Valve 48 to isolate from the brake pipe and vent to atmosphere the space to the left of triple piston I6. The duration of the emergency electrical impulse is sufcient to vent this small volume and cause piston l5 to move outward its full traverse and seat on the front cap gasket. This is the well known emergency position in which the slide valve admits auxiliary reservoir pressure to depress piston 24 and open check 28, whereupon brake pipe air flows past check 21 to brake cylinder.

From the above it is apparent that electrical venting in emergency, initiates at each triple valve emergency venting of the brake pipe to the brake cylinder.

Aside from the special ports and the double beat electrically actuated valve above described the front cap 45 conforms to existing standards and has a conventional graduating stem 54 with graduating spring 55.

An ordinary, freight-type, auxiliary reservoir is illustrated at 56 and this has the usual triple valve seat 5'I from which leads the brake cylinder pipe 58. Instead of seating the triple valve body II on seat 51, a ller piece 59 is interposed. This has a central passage GI to connect the auxiliary reservoir with the slide valve chamber, a passage 62 connecting brake cylinder port 34 with pipe 58 and a measuring chamber 63 for electrical quick service venting. There are also certain passages, later described.

A pipe 64 connects exhaust passage 33 of the triple valve with a passage 65 in filler piece 59 and body 65 bolted thereto. Port 65 leads to seat 61 in the valve chamber 58. The release valve is shown at 69 and is closed against seat 51 when winding 'II is excited. Spring 'l2 normally holds the valve B9 open, the winding TII being normally inert. Air exhausted through seat 6l, passes through a manually set retainer 'I3 of the usual form.

The body 66 contains a slide valve chamber I4 and a cylinder 'l5 closed by a cap l5. A piston 'I'I works in cylinder l5 and is urged to the right by spring 18, the piston being guided by a stem I9, which is formed to confine and thus positively actuate a slide valve 8i. In the seat for slide valve SI is a port 82 leading to measuring chamber B3 and a port 83 leading to brake cylinder passage 62. A ball check valve 84 permits flow in port 83 only in a direction toward passage 62.

The slide valve 8l has a loop port 85 which under normal conditions connects ports 82 and 83 so as to vent chamber 63. Remembering that chamber 63 measures the reductions effected by electrical quick service, it will be apparent that in a split reduction application, rising brake cylinder pressure causes an increasing charge to be retained in chamber 63, so that the quantity of air vented decreases on successive reductions. If such decrease on successive reductions is not desired the measuring chamber may be Vented to atmosphere instead of being vented to the brake cylinder, this being a familiar practice in the quick service venting art.

The slide valve 8| has a through port 86 which, in the outward (lefthand) position of valve 8l, registers with port 82 (see Fig. 9). Valve chamber 'I4 is connected with brake pipe 43 by pipe 81 and passage 88 so that ports 85 and 82 are quick service vent ports.

The piston TI, normally held to the right by spring 18, is moved to the left by depleting the pneumatic pressure on its outer (left) side. This space is normally charged to equality with the pressure in chamber 74 by a restricted port 89 leading through piston 77. It may be vented at a rate greater than charging ow through port |39 by forcing valve 9| from its seat against the opposition of spring 92 and the unbalanced pressure acting on the valve. The winding 93, when excited, performs this function. It is normally inert, but for service reductions is excited long enough to vent the space to the left of the piston 77 and permit equalization between the pressures in the brake pipe @i3 and in chamber 63.

It is desirable that an emergency application initiated pneumatically (for example by a burst brake pipe hose) should be propagated electrically throughout the train, so as to limit slack action. For this purpose a pneumatically actuated switch is associated with the brake pipe at each triple valve. A convenient way is to interpose body 91| between pipe 27 and filler piece 59. 'Passage tt extends through body 9d, a restricted port 95 leads from passage 88 to chamber 95 and a larger port Q7 leads to a smaller chamber 9B. A flexible diaphragm 99 separates these chambers. Thus a sudden reduction of brake pipe pressure would cause diaphragm 99 to move to the right quite forcibly while a slow reduction would have little or no effect.

The diaphragm 99 when forced to the right acts through a plunger ||JI to shift contactor ||i2 into engagement with fixed contact |83. A spring lil!! resists such motion, and is of such strength as to preserve the desired functional distinction between service and emergency` reductions of brake pipe pressure.

Referring now to Fig. 2, it will be observed that control of the electrical circuits is effected by pneumatically operated switches which are controlled by an engineers brake valve in consonance with the direct pneumatic control exercised through the brake pipe.

A main reservoir |95 of ordinary form and charged in the usual way, supplies air through main reservoir pipe |06 to the engineers brake valve. The brake valve has the usual sectional body Ilil, cap Ilit, rotary valve IES, subject on its top to main reservoir pressure, actuating handle I||, equalizing discharge piston ||2 and discharge valve IIi actuated thereby. In the `seat for the rotary valve are the customary ports, as follows, governor port H4, feed valve port IIE), brake pipe port IIB, with branch ||7, preliminary exhaust port lill, equalizing reservoir port IIe, exhaust port I2I with branch |22, control reservoir port |23, release port |24 and sanding port |25.

The porting of the rotary valve |99, as to the normal seat ports above described is conventional, the following functions being performed in the positions named.

Running position (Fig. 2) .-Governor port IM subjected to main reservoir pressure. 'Brake pipe port ||6 connected with feed valve port 'H5 and equalizing reservoir port H9. Release port |24 connected to exhaust.

Release position (Fig. 3).-Grovernor port IM subjected to main reservoir pressure. Feed valve port ||5 connected to branch exhaust port |22 for warning purposes. Brake pipe port ||6 and equalizing reservoir port I |9 fed with main reservoir air.

Electric holding position (Fig. 4).-Same as running position, except that release port |24 is blanked to hold engine brakes.

Service position (Fig. 5) .-Feed valve port ||5 subject to main reservoir pressure. Preliminary exhaust port ||3 connected with exhaust port |2| Lap position (Fig. 6).-Feed valve port ||5 subject to main reservoir pressure.

Emergency position (Fig. 7).-Main reservoir pressure admitted to control reservoir port |23. Brake pipe branch port I7 and equalizing reservoir port I I9 both connected to exhaust port i2 Sanding po-rt |25 fed by main reservoir.

In addition to the normal porting the seat of the rotary valve has two additional ports, an electric service port |26 and an electric release port |27.

The rotary valve IBS is so ported that the following control of ports |25 and |27 is secured.

Running position (Fig. 2) .--Both ports |25 and |27 blanked.

Release position (Fig. 3) Port |26 blanked. Electric release port |27 subject to main reservoir pressure admitted by port |23.

Electric holding position (Fig. 4).-Port |26 blanked. Electric release port |27 subject to main reservoir pressure admitted by port |23. Observe that electric holding position is the same as release as to ports |25 and |27 and the same as running as to ports H5, IIb, ||7 and it.

Service position (Fig. 5) .-Brake pipe port ||6 is connected by loop port |29 with electric service port |26, while release port |27 is blanked.

Lap position (Fig. 6) .-Both ports |25 and |27 blanked.

Emergency position (Fig. 7).--Both ports |26 and |27 blanked.

The port |2l leads by way of a connecting` pipe to chamber I3I which is constantly vented to atmosphere by way of choke Pressure developed in chamber I2| by the ope--ing of port |27 to main reservoir pressure, acts on a piston |33 against the opposition of spring itt, and tends to compress (and thus reduce the resistance of) a carbon pile rheostat made up of carbon disks |35 held in an insulating guideway it. The disks contact at one end with a terminal it?. The compressing plunger it?) at the other end is grounded. Between plunger |38 and piston |33 is a yielding telescopic connection it. Since the travel of piston |33 is limited, the connection |35) protects the rheostat against excessive compressive stress. The choke |22 and chamber ilil ensure slow increase of resistance offered by the rheostat after release, to prevent the occurrence of undesired application functions.

The electric service port |125 leads to the working space of a diaphragm motor which when subject to pressure closes a service switch. rhe motor diaphragm is shown at Mil, the switch contacts at |62 and the bridging contactor at |43. The contacter is forced toward the contacts by the diaplfuagm and is normally held away from them by spring |416. A branch of port |25 leads through a small choke Ille to the discharge passage from the equalizing discharge valve H3, between valve M3 and an exhaust choke IAB. The purpose of this is to hold the switch |l3 closed in lap position until valve ||3 closes or is about to close.

The effective volume above piston ||2 is, as usual, increased by connection with an equalizing reservoir itl. The pressure in the equalizing reservoir when above a chosen low value, say 20 pounds gage, acts to hold a diaphragmactuated multiple pole emergency inhibiting switch closed and thus establish paths through which the two main operating circuits are grounded by the closing of another switch when it is desired to produce an emergency application.

The diaphragm appears at |48 and two sets of contacts at |49 and |5| respectively. There are two bridging contactors |52 and |53 carried on an insulating disk e, the disk being urged in a circuit closing direction by the diaphragm and in the opposite direction by a spring |55.

Both the circuits established by the switch justJ described may be simultaneously connected to ground to product an emergency application, by a diaphragm actuated emergency switch subject to pressure in the sander port |25. Pipe |56 leads from port |25 both to the emergency relay vent valve E51 (as usual) and to the space to the left of diaphragm |58 arranged to close a single bridging contactor |69 against the contacts ISI, |62 and |63 simultaneously. Contact |63 is grounded and contacts |62 and |63 are connected respectively each to one of the contacts |99 and |5I. Thus, if contact |59 closes while contacts |52 and |53 are closed, both circuits are grounded.

It should be remembered that the conventional relay vent valve includes a vent port through its piston so that pressure in pipe |56 will bleed away in all positions of the engineers brake valve except emergency position.

Means to produce a brake application, if the electric circuits become deranged, are provided.

A double-beat valve |64 in chamber |65 connects that chamber alternately with the main reservoir, or through choke |66 and whistle |61 to atmosphere. When either connection is open the other is closed. The normal condition is with winding |68 energized and the atmospheric vent port closed by valve |64. This charges timing reservoir |69 to main reservoir pressure. The pressure in this chamber acts to close an emergency valve, which when open admits main reservoir air against the diaphragm |56, irrespective of the position of the engineers brake valve.

The emergency valve just mentioned comprises a body |1| and two flexible diaphragms |12 and |13, of which |12 is materially the larger. The diaphragme are connected to iiex in unison by a spacer |14 formed on its lower end with an annular valve rib |15 coacting with seat below the smaller diaphragm. A port |11 leads from the space within rib |15 to the space between the diaphragms. The space above diaphragm |12 is connected to the timing reservoir, the space between the diaphragms with sander pipe and the space below the lower diaphragm with main reservoir pipe |96.

If winding |63 be deenergized the timing reservoir |69 is isolated from the main reservoir and starts to discharge slowly. After a definite time interval valve |15 will open and cause diaphragm switch |58, |59 to close and produce an emergency application. The time interval is to permit the engineer, if he so desires, to reenergize winding E63 by closing a forestalling switch. In doing so he acknowledges the signal that the electric circuits are out of order or ineffective, and that he is dependent on pneumatic brake operation. Deenergization of winding |63 results from derangement of the circuits, as will hereinafter be described.

A threeway cock |18 is provided and when turned 90 counterclockwise from the position shown, opens a bypass |19 to supply main reservoir air to reservoir |69 and at the same time isolates chamber |65 from reservoir |69. This suspends the automatic electric emergency mechanism and is necessary to operation if the electric system is inoperative.

The various electrical circuits will now be described with particular reference to Fig. 1.

On the locomotive are two sources of direct current, of normally equal voltage, one of which is provided with means to increase its voltage relatively to the voltage of the other. These two sources supply two lines extending throughout the train and called the service line and the emergency line.

In the example illustrated, the service generator indicated by numeral |8| applied to its armature has a normal shunt field winding |82 and an auxiliary shunt eld winding |83 which last is fully excited only when increased voltage is desired. The carbon pile rheostat |35 (Fig. 2) exclusively controls excitation of winding |83. The emergency generator indicated by numeral |89 applied to its armature has a shunt eld winding |85.

The two generators are preferably driven in unison by a single means, such as a turbine and deliver to their lines, current of the same polarity and, when the auxiliary winding |83 is given its minimum excitation, are of substantially equal voltage. Similar terminals of the two generators are grounded as the track oiers a good ground return.

Service generator |8| is connected through protective resistance |86 with service line |81 which runs throughout the train, and emer-` gency generator |84 is connected through a similar protective resistance |38 to emergency line 589 which also runs throughout the train.

Paralleling these two lines is a supervisory line |9| which has no connection with either of the other two lines except on the locomotive and the Caboose. The primary purpose of this line is to give a continuous indication of the condition of the electrical system, and particularly to indicate whether the electrical service and electrical emergency apparatus is effective. In addition to its supervisory functions the line l9| may form part of a telephone circuit, the permanent connection of instruments being indicated at |92 on the locomotive and at |93 on the Caboose. Similar connections might be afforded by the use of jacks |94 on the cars, so that a brakeman might plug in a portable set at any car in the train. Such a telephone circuit would operate independently of the supervisory functions of the line |9| and could involve any suitable refinements of the telephone art.

All the apparatus shown in Fig. 2 is located on the locomotive, and connections can be traced on that figure in such a way as to show the relation between the brake valve and related parts which form normal pneumatic control, and the pneumatically actuated electric switches and similar devices which coordinate the responses of the electrical devices with the normal pneumatic responses of the brake system. The same data is shown in diagrammatic form in Fig. l.

The service line |31 and the emergency line itil are both connected to be grounded by the emergency switch and the connection of each to the emergency switch is subject to control by the emergency inhibiting switch which closes when a denite pressure is established in the accesso equalizing reservoir, the switch being actuated in a closing direction by the diaphragm |48. Thus the service line |81 is connected by wire |80 with one of the contacts |09, the other of which is connected by line |95 with contact |62 of the emergency switch. Similarly the emergency line |89 is connected by wire 200 with one of the contacts of the emergency inhibiting switch, the other contact |5| being connected by wire |98 with contact |6| of the emergency switch. The contact |83 of the emergency switch is grounded. Under normal running conditions the contactors |52 and |53 of the emergency inhibiting switch are closed, and it follows that if the contactor |59 of the emergency switch should close, it will ground both the service line |81 and the emergency line |89. The emergency switch is the means by which an emergency application is produced either under the control of the engineers brake valve or under the control or" the supervisory relay, as will be hereinafter explained.

The reason for grounding both the service and the emergency line is to avoid a condition under which the voltage of the service line would be higher than the voltage of the emergency line, this relation being availed of to establish the releasing or the release retaining function.

To produce service applications by causing quick service Venting of the brake pipe at each of the triple valves, means must be provided to ground the service line |81 without grounding the emergency line, and in order to produce repeated or cyclic venting of the brake pipe at each triple valve, it is desirable to provide means which will cause such venting to recur as long as the equalizing discharge valve on the engineers brake valve is open.

This ground connection for the service line can be traced as follows: Branching oif from the line |99, which is connected to the service line |81, as above described, is a lead to the winding |91 of the service cycling relay. The other terminal of this winding is grounded as shown. Excitation of the winding |91 (and the winding is normally excited) lifts the armature |88 from the stop |99 and draws it against the front contact 20|. The front contact 20| is connected by the wire 202 with one of the contacts |412 of the service switch, the other contact |92 being grounded.

Service switch contactor |83 is moved in a closing direction by the diaphragm |4I. As can readily be determined from an inspection of Fig.

5, the diaphragm |8| is subjected to pressure when the rotary valve is moved to service position, and thereafter, in either service or lap position, is kept under pressure so long as the equalizing discharge valve H8 is discharging at a rate exceeding the capacity of choke port |98. From this it follows that the service switch remains closed substantially as long as equalizing discharge flow is occurring at the engineers brake valve.

When the switch first closes the armature |98 is up. The effect is to establish a ground connection from service line |81 and the Voltage in line |81 to the rear of the connection |90 drops, and as will be explained later, the electric service mechanism on all the cars functions to discharge a measured amount of air from the brake pipe. Reduction of the voltage of the line |81 substantially deenergizes Vwinding |91 and armature |98 drops destroying the ground connection.

The voltage in the line |91 does not, however, regain its normal value until the service condensers hereinafter described as carried by the various cars are charged. When they are substantially fully charged, and the voltage of the line |81 approaches its normal value, winding |91 will again pick up armature |98. This reestablishes the ground connection and initiates a new venting cycle which takes place on every car because the condensers just mentioned have been recharged and are then permitted to discharge and actuate the service vent valve.

Since the time necessary to charge all the service condensers 22| is proportional to their total capacity and hence to the length of the train, the cycling will be slower on long trains than on short ones. Hence the development of brake cylinder pressures in service will be slower on long trains which is a desirable characteristic.

The supervisory line |9| leads throughout the train and operates through a supervisory relay to control a signal lamp and the winding |08 of the automatic emergency magnet valve. Current to energize this winding and lamp are supplied by a line 203 which leads from the ungrounded terminal of the emergency generator |80. A branch 204 leads to the lamp 205 and a branch 200 leads to the winding |08. The second terminal of the lamp 205 is connected to the armature 208 and the second terminal of the winding |68 is connected to the armature 209 which are lifted when the winding 201 of the supervisory relay is sufficiently energized. One terminal of the winding 201 is connected directly with the line |9| and the other terminal is grounded. The relay has two front contacts 2H and 2|2, both grounded and coacting respectively with the armatures 208 and 209. Consequently when the current flow in the supervisory line |9| is normal the winding 201 is fully excited and the armatures 208, 209, are raised against the front contacts, the lamp 205 burns and the winding |68 is excited. Means are provided on the caboose to insure a normal supply of current to the line |9| from both the lines |81 and |89, when all lines are in normal condition and also during the normal functioning of the electric system, but if any line becomes deranged the supply of current to line |9| is reduced, reducing the excitation of winding 201 to a value such that the armatures 208 and 209 will drop to the back contacts, which are merely stops. In such case the winding |88 becomes deenergized, the doublebeat valve |54 shifts and the slow bleeding of the timing reservoir |89 commences. The engineer is warned of this condition by sounding of the whistle |01 and the extinguishment of the lamp 205, and may, by closing of a ground switch 2|3, forestall the action of the emergency switch |59 whose operation has already been described. In this forestalling action the engineer recognizes that the electrical equipment is inoperative and that he is dependent solely on pneumatic operation of the brakes.

Each car, including the Caboose, is equipped with electrical apparatus which will now be described, such apparatus controlling energization of the windings 53, 1| and 93, whose functions have been explained with reference to Fig. 8.

On each car the electrical equipment is connected to the service line |81 by a lead 2M and to the emergency line |89 by a lead 2|5. Since the equipment on all the cars is the same, the

illustration in Fig. 1 has been limited to the equipment of one freight car. There would be a similar equipment on the caboose, and this fact is there indicated merely by the illustration of the leads 2|4 and 2I5. The caboose alone carries certain portions of the supervisory mechanism, as indicated in Fig. 1.

The equipment on each car comprises three units, first, a service unit which may operate independently of the other two units. Second, an emergency unit which may operate independently of the other two units, but preferably includes a grounding switch for grounding the service line when the emergency mechanism responds in emergency. The third unit is a release unit. The latter is so arranged as to derive its charge under running conditions from the service line and the emergency line equally and to remain inactive while the voltages on these two lines are the same or substantially so. When, however, the voltage of the service line is raised materially above the voltage of the emergency line, the effect is to cause a substantial current flow through the release magnet winding 1| to cause initial response of its armature after which current ilow incident to the differential voltage will maintain the armature of the magnet valve in its shifted position.

The service lead 2|4 is connected to one terminal of an asymmetric resistance device 2| 6, preferably a copper copper-oxide rectier. A wire 2|1 leads rom the other terminal of the rectier to one terminal of the winding 2|8 of the service relay S. The other terminal of this winding is connected by wire 2 I 9 to one terminal of an electrostatic condenser 22|. The other terminal of this condenser is connected through the winding 93 of the service magnet valve to ground.

The relay S has an armature 222 which when drawn against the front contact 223 connects the line 2|4 to ground by way of the wire 224. Assume now that the service line I81 is grounded. A discharge circuit for condenser 22| is immediately established from condenser 22| through wire 2I9, winding 2|8, Wire 2I1, asymmetric resistance unit 2I6, wire 2I4, service line |21, to ground, to winding 93 back to condenser 22|. The condenser starts immediately to discharge and the resulting excitation of winding 2|9 lifts the armature 222 and establishes a local ground on the car, so that the service line |81 is quickly shunted out of the discharge circuit. This insures rapid discharge of the condenser 22| sufcient to insure intense energization of the winding 93, and also grounds the service line I 81 locally to hasten the response on adjacent cars.

The emergency circuit is quite similar. Lead 2|5 is connected to one terminal of the asymmetric resistance device 226, thence by wirey 221 to one terminal of the winding 228 of the emergency relay E. The other terminal is connected by wire 229 to one terminal of the electrostatic condenser 23|, whose other terminal is connected through the Winding 53 of the emergency magnet valve to ground.

The emergency relay E controls two armatures 232 and 233 which are drawn respectively against front contacts 234 and 231 when the winding 22S is energized. The front contact 234 is connected through a resistance 236 with the lead 2|5, while the front contact 231 is connected through wire 238 with the lead 2|4.

Assume now that the emergency line |89 alone is grounded or that both the emergency line |89 and the service line |81 are grounded. In either case a discharge path for the condenser 23I will be established as follows: from condenser 23|, through wire 229, relay winding 228, Wire 221, resistance device 226, lead 2I5 and emergency line |89 to ground to winding 53 and back to condenser 23|. As soon as discharge ow occurs relay E will pick up its armatures 232 and 233. Armature 232 will establish a local ground circuit, insuring rapid discharge of the condenser 23| and local grounding of the emergency line. Armature 233 by closing against contact 231, will ground the service line |81, insuring local grounding of this line.

It will be recalled that the contacter |02 is arranged to close against the contact ID3 (see Fig. 8) if brake pipe pressure is reduced at an emergency rate, as it might be, for example, by a burst hose. The effect of the closing of these contacts is to ground the emergency line |89. Ensuing response of the emergency relay will immediately ground both the emergency and service lines, as just described.

The asymmetric resistance devices 2H:` and 226 are so contrived that they limit charging ow from the service line and the emergency line respectively to condensers 22| and 23|. This limitation not only keeps the maximum current flow in the service and emergency lines within reasonable limits, but it also limits the current flow through the relay windings 2|8 and 22S and through the service magnet winding 93 and emergency winding 53 to values low enough to insure that the relays and magnets remain inert during charging. On the other hand reverse rlow is subject to relatively low resistance so that discharge of the condensers can occur comparatively freely.

The release unit, as stated, is interconnected with the service and emergency units. The lead 2|4 is connected to the wire 238 and to this wire is connected one terminal of an asymmetric resistance unit 24|, so arranged as to offer its less resistance flow away from the service line and its greater resistance to ow toward the service line. The other terminal of this resistance unit is connected by wire 242 with one terminal of a winding 243 of the release relay R. This winding 243 has a tap at its middle. The other terminal of the winding 243 is connected by wire 244 with one terminal of release magnet winding 1I. The other terminal of release magnet winding 1I is connected by wire 245 through resistance 236 and lead 2|5 with the emergency line |89.

The release relay R has a iront contact 246 which is connected with the wire 245 and a back contact 241 which is connected through a resistance 243 with ground. The normal condition of the relay is that shown in the drawings in which it is inert and the armature 249 is against the contact 241. Under these conditions there is charging flow from beth the service and the emergency lines to the condensers 25|. This iiow can be traced as follows. From service line |81 through lead 2|4, asymmetric resistance device 24|, upper half of winding 243, wire 252 to condenser 25|, the other terminal of the condenser being grounded through arrzrature 249, back contact 241 and resistance The ow from the emergency line is by way of lead 2| 5, resistance 236, wire 245, winding Il, wire 244, through the lower half of winding 243, and thence through wire 252 to condenser 25! and thence to ground, as before.

The resistance 2138 is so proportioned as to limit the charging current to a suitable value. The function of the resistance 23S is to balance the charging currents flowing from the service and the emergency lines. The relay R will be inert because if the two currents are equal they will neutralize each other in passing reversely through the two halves of the winding Thus during charging the relay remains inert.

If, however, the voltage in the line itl be raised, and this result is produced when desired by compressing the carbon rheostat l35 and rendering the auxiliary field winding i253 effective. The relay R will be thrown out of balance, armature 2li@ will be drawn against contact 2%, and the condenser 255i will discharge, the path of discharge being from one terminal of the condenser, wire 252, through the lower portion of winding 2153, wire 2M, release magnet winding il, wire 245, front contact 245 to armature 2&9, to the other terminal of the condenser. This will excite winding il and shift its armature, closing the valve lie (Fig. 8) and thus closing the exhaust port of the triple valve.

At this time the asymmetric resistance 2l-|| prevents back flow to the service line, which would otherwise occur, because the condenser voltage and emergency line voltage are cumulative.

After the armature of release valve magnet 'li has shifted, it is held in its shifted position by current flow as a result of the sustained difference in voltage between the service and the emergency lines. This flow occurs by way of lead 2li, through resistance device 2M, winding 2&3, wire 2M, winding Il, wire 225, resistance 23S and lead 2i5 to the emergency line |85.

The supervisory equipment on the Caboose involves means for connecting both the emergency line and the service line to the supervisory line, in such a way that if any one of the three lines becomes deranged, the supervisory relay 2M on the locomotive will be partially or wholly deenergized. To effect the desired result the service line iii'i is connected to the winding 255 of a polarized relay, the other terminal of whose winding is connected through an asymmetric resistance device 25E favoring flow away from the service line. The other terminal of the asymmetric resistance device 255 is connected by wire 259 and a milliammeter 25| with the supervisory line itl. The emergency line |89 is connected through two approximately equal resistances 25'l and 25%, connected in series, to the line 259. The sum of the resistances 251 and 258 approximately equals the sum` of the resistance of winding 255, and the resistance of 255 to flow toward line 259. Consequently, the lines itl and ills normally furnish substantially equal currents at the same voltage to the line 259. l

When current is flowing from line i8? to line 259, and also when no current is flowing through winding 2557 the armature 252 of the polarized relay remains against inert stop 253, but if flow in the winding 255 reverses the armature 2te shifts against Contact 252. Since the armature 262 is connected to the wire 259, and since the contact 254 is connected by wire 255 between the resistances 251 and 258, the effect is to shunt out the resistance 258. It follows that if the service line |81 is grounded, as it is to produce a service application, the relay armature 262 will shift and reduce the resistance between the emergency line |89 and the supervisory line. At this time the emergency line alone furnishes current to the supervisory line and the shifting of the armature by reducing the total resistance of the circuit, permits maintenance of an adequate current flow through the supervisory relay 257| on the locomotive and prevents this relay from producing an emergency application.

When the armature 252 shifts, the armatures 258 and 2tlg of the supervisory relay will drop momentarily and the blinking of the light 2ii5 will indicate to the engineer that the polarized relay on the caboose is operating normally.

The above gives a general outline of the circuits. The relation of the capacity of each condenser to the inductance of the associated relay winding, and magnet valve winding, will control circuit characteristics and these values can be so chosen, according to known principles, that the maximum current owing, the time required to complete charging, and the discharge circuit characteristics are such as to meet the service requirements. When the system is charged, the service and emergency line voltages at the rear end of the train will approach the voltages available at the terminals of the two generators. Consequently, the use of large conductors for the service, emergency and supervisory lines is unnecessary. For similar reasons no unusually rigorous requirements are placed upon the efficiency of the jumper contacts between cars.

When the system is fully charged the Vcurrent flow in the circuits is merely the aggregate of the leakage currents of the condensers, and since such leakage is small in well designed condensers, the waste of electrical energy in the system is remarkably small.

The functions of the various pieces of apparatus have been explained in connection with the description of the apparatus, and only a very brief general description of operation is considered necessary.

The strictly pneumatic functions of the brake conform to those now standard. As it can reasonably be assumed that any one skilled in the art is familiar with these functions they will be given only the briefest mention.

OPERATION Running position (scc particularly Fig. 2)

In this position the brake pipe and the equalizing reservoir are fed by the feed valve. The locomotive brakes are released through the release port. In this position the sander port 25, electric service port |25 and the electric release port |2'l are all blankeol so that the emergency switch 59 is open, the service switch |653 is open and the carbon pile rheostat |35 is free of pressure. Under these conditions the voltages in the service line |87 and emergency line it are equal. The various condensers will charge as described and the apparatus on the caboose will assume the position as shown in Fig. l. It should be observed that in this position the equalizing reservoir |49 is charged so that the emergency inhibiting switch will be closed and the system will be conditioned for electric emergency actuation.

Service position (sce Fig. 5)

In this position the equalizing reservoir is slowly vented, as usual, and the port |29 admits brake pipe air to the electric service port |26,

closing the electric service switch |43. The engineers brake valve is allowed to remain in service position only long enough to establish the desired reduced pressure in the equalizing reservoir ELEG. It is then moved to lap position. In lap position the port 29 ceases to connect the brake pipe port with the electric service port, but so long as the equalizing discharge valve I I3 delivers air to the exhaust tting at a substantial rate, the service switch |43 will remain closed. The closing of this switch establishes a ground connection from the service line i8? through the line i9@ (see Fig. l) and the service cycling relay is? performs its cycling function already described. This alternately discharges the condenser 22| through the service magnet winding 5:3, then recharges the condenser, and again discharges it through the winding S3, such cycles recurring as long as the service switch remains closed, that is, as long as the equalizing discharge valve is actively discharging air from the brake pipe. Each time the magnet valve winding s3 is excited, the piston moves to the left and discharges air from the brake pipe into the measuring chamber 53. As soon as the winding is deenergized the pressures on the piston 'il equalize so that the piston moves back and pressure is equalized between the chamber 63 and the brake cylinder. Consequently the cycling action of the relay i'! causes recurrent quick service venting of the brake pipe, the amount of air vented diminishing with each successive Venting. When the equalizing discharge valve closes, the service switch opens and the cycling relay closes. Should the pressure in the equalizing reservoir be further reduced, the service switch will again close the cycling relay will resume its operation and continue in operation until the equalizing discharge valve closes or substantially closes.

Emergency position (FigA 7) Ii the engineers brake valve be moved to emergency position the pneumatic functions characteristic of the ordinary pneumatic operation take place. One oi these is the admission of main reservoir air directh7 to the sanding port E25. This causes the operation or the emergency relay valve and also causes the contacter 58 of the emergency switch to close against the contacts |611., |62 and I-, the emergency inhibiting switch being closed by equalizing reservoir pressure on the diaphragm |48. The effect of the closure of the switch |59 is to ground both the service line |87 and the emergency line This produces energization of the emergency magnet valve winding 53 and resuts in isolation of the space to the left of the triple piston it and the sudden venting of that space to atmosphere. Consequently the triple valve makes its full travel to emergency position, the emergency piston 24 is forced down and brake pipe air is admitted to the brake cylinder to augment brake cylinder pressure in the usual manner.

The grounding of both the service and the emergency lines deenergizes the supervisory line and consequently deenergizes winding |68 of the supervisory magnet valve. This vents the timing chamber EES so that after the normal time interval the emergency valve |74 will shift and admit main reservoir air directly to the sanding pipe Release after emergency The emergency function is accompanied by the Venting of all the air from the equalizing reservoir |49 and when equalizing reservoir pressure reaches a low value, say twenty pounds, the emergency inhibiting switch |54 will open. This interrupts the connections through which the emergency and service lines are grounded in emergency application. The effect is to permit reestablishment of the normal voltage in the service and emergency lines which will be followed by the recharge of the condenscrs throughout the train. The reestablishment of this voltage will cause the supervisory relay 257 to lift its armatures 268 and 259, thus causing the excitation of the winding i of the supervisory magnet valve. This terminates the venting of the timing reservoir |69 and recharges that reservoir, closing the emergency valve |14. Consequently, as soon as the rotary valve |89 is moved from emergency position, the pressure in the sanding pipe |55 will 1bleed away through the vent port in the emergency relay Valve |51. The emergency switch |59 will then open. When this condition has been established, and this is indicated by the relighting of the lamp 295, the engineer may move his brake valve to a releasing position, such as full release, running or electric holding position, and recharge the system pneumatically.

Release position (Fig. 3)

In this position main reservoir air is admitted through the port |28 to the electric release port |27. This compresses the carbon pile rheostat, raises the voltage in the service line |8'i, and, in the manner already described, excites the windings of the release magnet valves and closes the valve 69 against exhaust of brake cylinder pressure. In this way the auxiliary reservoirs may be recharged without releasing the brakes.

Electric holding position To prevent overcharging of the brake pipe, the engineer shifts his brake valve to the electric holding position (Fig. 4), after a denite period in full release position. In this position the brake pipe is fed with air from the reed valve instead of being fed with air at main reservoir pressure, and in all other respects the pneumatic functions are similar to those characteristic of the well known holding position. In electric holding position the port |28 still registers with the electric release port |27 so that the valves 69 throughout the train are held closed and brake cylinder pressure is retained.

Running position If the engineer now desires to release or reduce brake cylinder pressure, he may shift the brake valve handle to running position (Fig. 2). In this position the electric release port |21 is blanked and the pressure in chamber i3| leaks away slowly. Slow release of this pressure is important because rapid reduction of the voltage on the service line I6? will cause response of the service relay S and initiation of an undesired service application. Since the releasing flow from the triple valves is slow, it is possible for the engineer to reclose the valves 69 throughout the train by shifting the engineers brake valve back to electric holding position. In this way there is limited provision for graduated release of the brakes.

If the engineer desires to avoid retention of brake cylinder pressure, he may shift his brake valve directly to running position, avoiding release and electric holding positions. If this practice be followed the release magnet valve Winding 1| will not be energized.

Automatic emergency initiated by supervisory circuit It has already been explained that during the normal functioning of the electric mechanism current is supplied continuously to the supervisory line, keeping the winding 201 of the supervisory relay fully energized.

If the energization of Winding 201 is reduced below a definite critical value, the fact will be signalled to the engineer, first by the extinguishment of the light 205, and second, by the blowing of the whistle |61, and he is thus warned that an automatic emergency application will follow after a time interval fixed by the volume of reservoir |69 and the size of port |66, unless he acts to forestall it.

The energization of winding 201 will be reduced below the critical value above mentioned. if either operating line |81 or |89 be broken, and if the supervisory line be broken winding 201- Will be completely deenergized. If service line |61 be broken and not grounded current flow through winding 255 ceases but does not reverse. Hence line |89 alone furnishescurrent to supervisory line |92 through both resistances 251 and 259 in series. This reduces the current flowing sufciently to cause relay 201 to drop armatures 2|| and 2|2. If line |89 be broken, line |81 alone will furnish current to line 9| through winding 255 and resistance device 256. The reduction in current flow in line |9| causes relay 201 to drop its armatures.

If the engineer immediately closes the forestalling switch 2|3, he will reenergize the winding |63 and prevent the occurrence of an emergency application, but he is advised by the necessity ofclosing this switch that the electric system is out of order and that he must rely on strictly pneumatic operation. If he does not close the switch 2|3 the venting of timing reservoir |69 will cause response of the emergency valve |14. This will admit main reservoir air toactuate emergency relay valve |51 and emergency switch |59. Consequently emergency application will be initiated both pneumatically and electrically regardless of the position of the engineers brake valve.

In its broadest aspects the invention involves the idea of -providing some means on each car for storing electrical energy, trickle charging this storage means from electrical train lines at rates which will keep the current flowing in the train line to a reasonably low value, and which will preclude the response to such charging flow of relays or magnet valves intended to control the brake functions on the car. The scheme also contemplates the association with the storage means of some device, such as a relay which is sensitive to conditions in the charging circuit and which may, through manipulation of the charging circuit, be actuated to bring about discharge of the storage device through the Aelectric mechanism arranged to control the brakes. This scheme may be embodied with various specifically different storage devices, so that while a condenser is preferred, the invention is not strictly limited to the use of a condenser. Similarly, while an asymmetric resistance device of the copper copper-oxide type is preferred to secure trickle charging of the storage device without impairing the ability of that device to offer a rapid discharge, other asym-f metric resistance devices or valves are known, and their possible substitution is within the broad scope of the invention.

The embodiment of the invention with the K triple Valve is necessarily subject to some of the limitations inherent in that triple valve, but the description is intended to be illustrative and not limiting. The invention resides primarily in the electric system and not in its specific application to any particular pneumatic system. Circuits of the type described might be used to control three functions of any type of brake valve, or a greater number of such circuits might be used, if it be considered desirable to control electrically a greater number of functions than the three here described. Moreover, while I prefer to make use of pneumatically actuated switches subject to primary control of an engineers brake valve, other schemes for controlling the electric circuits associated with such valves have heretofore been proposed, and might be adopted in particular cases without departing from the broader aspects of the present invention.

What is claimed ist- 1. A fluid pressure braking system comprising an electric energy storage device; means for trickle-charging said device; an electrically operated fluid pressure brake incapable of respondn ing to said trickle-charging current but responsive to discharge of current from said energy storage device; and means for causing discharge of said device to actuate said brake.

2. A braking system comprising electrically operable brake controlling means, a source of current; an electric energy storage device; means for charging said device from said source; and means for establishing a low resistance path across the terminals of the energy storage device to cause discharge thereof to operate said brake controlling means.

3. A fluid pressure braking system comprising a fluid pressure brake; electrical operating means for said@ brake; an electrostatic condenser; means. for charging said condenser; and means for causing discharge of said condenser through said electrical operating means to operate said brake.

4. A braking system comprising a brake; electrical controlling means for said brake; an electrostatic condenser; a source of electric current for charging said condenser; an asymmetric resistance interposed between said source and said condenser to limit the charging current supplied to said condenser to a value insufcient to actuate said electrical brake controlling means, but to permit substantially free flow of discharge current from said condenser; and means for causing discharge of said condenser through said electrical operating means.

5. A braking system of the closed circuit type comprising a fluid pressure brake having release, service, and emergency functions; electrically operated means associated with each of said functions; a plurality of electrostatic condensers, each arranged to supply operating current to a corresponding one of said means; a source of current for charging said condensers; and means for selectively discharging said condensers through said electrically operated means to cause said brake to carry out one or more of its functions.

6. A braking system comprising a fluid pressure brake; means including an electrically controlled valve for causing operation of said brake; a source of electric current; an electrostatic condenser; means for charging said condenser' from said current source; a relay device for causing operation of said valve by current discharged from said condenser; and means for causing discharge of said condenser to pick up said relay device and operate said valve to operate said brake.

7. A braking system comprising a fluid pressure brake; electrically controlled valves for causing service and emergency brake applications selectively; service and emergency lines; separate means for supplying current to each of said lines; an electric energy storage device connected to each of said lines; an asymmetric resistance element interposed between each of said devices and the associated line to cause said devices to be trickle-charged from the lines; a relay device in circuit with each of said energy storage devices, said relay devices being nonrespcnsive to the trickle-charge current but responsive to discharge current from said electric energy storage devices; and means for establishing a low resistance ground on either the service or emergency line to cause operation of the associated relay device and to initiate a brake application.

8. A braking system comprising a service line and an emergency line; means for supplying electric current to said lines; a plurality of electrostatic condensers arranged to be charged from said lines; a service relay interposed between one of said condensers and the service line; an emergency relay interposed between another of the condensers and the emergency line; a release relay interposed between a third condenser and the two lines, said release relay being arranged to remain balanced so long as balanced currents ilow to it from said lines; uid pressure braking means under control of said relays; and means for establishing a low resistance circuit for each of said condensers selectively to cause operation of said braking means or to release the same.

9. A braking system comprising a source of electric current; iiuid pressure braking means; an electrostatic condenser; means for charging said condenser from said course; means responsive to discharge current from said condenser for causing operation of said braking means; a service switch for establishing a low resistance ground connection to said condenser to4 cause a brake application; a relay device controlling said connection; and means rendered active by the closing of said service switch to cause the relay to open and close said connection periodically.

l0. In a braking system a iiuid pressure brake; a source of current; an electrostatic condenser; means for charging said condenser from said source; electrical means responsive to discharge current from said condenser for causing operation of said brake; means for establishing a low resistance connection across the terminals of said condenser to discharge the same; and means including a supervisory circuit for giving a continuous indication of the condition of the charging means.

l1. A braking system comprising a fluid pressure brake and manually operable means for controlling it; electrically operable means supplemental to said manually operable means for controlling 'the operation of said brake; a source of current; an electric energy storage device; means for trickle-charging said device from said source; and means for establishing a low resistance ground across the terminals of said electric energy storage device to discharge the same through said electrically operable means to cause a brake application.

12. A braking system comprising a uid pressure brake and manually operable means for controlling it; electrically operable means supplemental to said manually operable means for controlling the operation of said brake; a source of current; an electric energy storage device; means for trickle-charging said device from said source; electromotive means for causing operation of the brake; means for establishing a low resistance ground across the terminals of said storage device to discharge the same through said electromotive means; and means for giving an indication of the condition cf the electrically operable means.

13. A braking system comprising a fluid pressure brake including manually operable means for controlling the same; electrical means supplemental to said manually operable means for controlling brake applications; a plurality of electrostatic condensers; two sources of current for charging said condensers; means for causing discharge of said condensers selectively through said electrical means to control brake applications; and electrical means normally energized from both said sources but responsive to voltage difference between them for controlling said fluid pressure brake to retain the brakes applied.

14. A braking system comprising a fluid pressure brake; electrically responsive means for causing operation of said brake; a plurality of electrostic condensers; a plurality of sources of current for charging said condensers; means for causing discharge of said condensers through said electrically responsive means to cause brake applications; and electrical means normally energized from both said sources and responsive to voltage diierence between them for causing a retaining operation of said electrically responsive brake-applying means.

15. A braking system comprising a uid pressure brake; electrically responsive means for operating said brake; a service line; means for supplying current to said service line; an emergency line; means for supplying current to said emergency line; an electric energy storage device connected to said service line and arranged to be charged therefrom; an electric energy storage device connected to said emergency line and arranged to be charged therefrom; means for causing discharge of said electric energy storage devices selectively through said electrically responsive means to cause service or emergency brake applications; a third electric energy storage device; means whereby said third device may be charged from the service line; means for boosting the voltage of the service line; and means energized from both said lines and responsive to Voltage difference between them to cause discharge of said third device to produce a retaining operation of said electrically responsive brake applying means.

16. A braking system comprising a iiuid pressure brake; electrically responsive means for actuating said brake and including electromotive means capable of performing a retaining action when energized; a service circuit and an emergency circuit; means for supplying electric current to each of said circuits, said currents being normally of approximately equal voltages; means for increasing the voltage impressed on one of said circuits; energy storing means arranged to be charged from both said circuits when their voltages are approximately equal; and means responsive to increase of voltage in one of said circuits to discharge said storing device through said electromotive device to initiate its retaining action.

17. The combination of a pneumatic brake system comprising a brake pipe extending throughout a train of vehicles, and reservoirs, brake cylinders and automatic brake valves connected therewith on the various vehicles; three electromotive devices associated with each such automatic valve, and each arranged to control a corresponding function thereof; two electrical circuits extending through the train; controllable means for supplying electric energy to each of said circuits; three means on each vehicle for storing electric energy, two of said means being connected to be charged individually from respective train circuits and the third jointly by both train circuits; two relay devices responsive to deenergization of the two circuits respectively and connected to discharge respective energy storing means individually charged from said circuits through corresponding electromotive devices; a third relay device responsive to an abnormal voltage relation between the two circuits to discharge the third energy storing means through the third electromotive device; and means comprising asymmetric resistance devices for protecting said relay devices against response to charging flow.

18. The combination dei-ined in claim 17, in which one of the two relays iirst-named functions when it operates also to deenergize the train circuit associated with the other of said two relays.

19. The combination defined in claim 17 in which the abnormal voltage relation between the two train circuits becomes effective to maintain the associated electromotive device active when such device has been rendered active by discharge from the energy storing device.

20. The combination defined in claim 17 in which the asymmetric resistance devices are rectifiers of the copper copper-oxide type.

2l. The combination of a pneumatic brake system comprising a brake pipe extending throughout a train of vehicles, and reservoirs, brake cylinders and automatic brake valves connected therewith on the various vehicles; three electromotive devices associated with each such automatic valve, and each arranged to control a corresponding function thereof; two electrical circuits extending through the train; controllable means for supplying electric energy to each of said circuits; three means on each vehicle for storing electric energy, two of said means being connected to be charged individually from respective train circuits and the third jointly by both train circuits; two relay devicesl responsive to deenergization of the two circuits respectively and connected to discharge respective energy storing means individually charged from said circuits through corresponding electromotive devices; a third relay device responsive to an abnormal voltage relation between the two circuits to discharge the third energy storing means through the third electromotive device; and means for protecting said relay devices against response to charging flow comprising asym-v metric resistance devices for the individually charged energy storing means, and a split winding in that relay device associated with the third energy storing means, such winding being so connected that the two currents which jointly charge the third energy storing device neutralize each other and maintain the relay inert.

22. The combination dened in claim 21, in which the abnormal voltage relation between the two train circuits becomes effective to maintain the associated electromotive device active when such device has been rendered active by discharge of the energy storing device.

23. The combination of a pneumatic brake system, comprising a brake pipe extending through a train of vehicles, and reservoirs, brake cylinders and automatic brake valves connected therewith on the various vehicles; three normally deenergized electromotive devices associated with each such valve and each arranged to control a corresponding function thereof; two electrical circuits extending throughout the train; controlling means for maintaining said circuits normally energized and deenergizing one or both at will, and for establishing an abnormal voltage relation between the circuits while maintaining both energized; three means on each vehicle for storing electric energy, two of said means being connected to be charged individually from respective train circuits, and the third jointly from both train circuits; two relay devices, each responsive to deenergization of respective train circuits and connected to discharge respective ones of the two energy storing means charged from individual circuits, through corresponding ones of said electromotive devices; a third relay device responsive to said abnormal voltage relation to discharge the third energy storing means through the third electromotive device; and means comprising asymmetric resistance devices for protecting said relay devices against response to charging currents.

24. The combination defined in claim 23 in which the asymmetric resistance devices are rectiers of the copper copper-oxide type.

25. The combination defined in claim 23 in which one of the two relays first named functions when it responds todeenergize locally both train circuits, and the other functions to deenergize locally only the train circuit associated therewith.

26. The combination of a pneumatic brake system, comprising a brake pipe extending through a train of vehicles, and reservoirs, brake cylinders and automatic brake valves connected therewith on the various vehicles; three normally deenergized electromotive devices associated with each such valve and each arranged to control a corresponding function thereof; two electrical circuits extending throughout the train; controlling means for maintaining said circuits normally energize-d and deenergizing one or both at will, and for establishing an abnormal voltage relation between the circuits while maintaining both energized; three means on each vvehicle for storing electric energy, two of said means being connected to be charged individually from respective train circuits, and the third jointly from both train circuits; two relay devices, each responsive to deenergization of respective train circuits, and connected to discharge respective ones of the two energy storing means charged from individual circuits, through corresponding ones of said electromotive devices; a third relay device responsive to said abnormal voltage relation to discharge the third energy storing meansk through the third electromotive device; and means for protecting said relay devices against response to charging currents comprising asymmetric resistance devices for the individually charged energy storing means, and a split winding in the relay device associated with the third energy storing means, such winding being so connected that the two currents which `iointly charge the third energy storing device neutralize each other and maintain the relay inert.

27. The combination of a pneumatic brake system comprising a brake pipe extending throughout a train of vehicles, and reservoirs, brake cylinders and automatic brake valves connected therewith on the various vehicles;

electrically actuated quick service vent valves, associated with the brake pipe on the various vehicles; an electrical circuit extending throughout the train; means for maintaining said circuit normally energized; a service switch for deenergizing said circuit; electric energy storing means in the various vehicles, connected to be charged from said circuit; a relay device one on each of the various vehicles responsive to deenergization of said circuit and connected to discharge the energy storing device in the same vehicle through the electric actuation portion of the corresponding quick service vent valve on such vehicle; means for protecting each such relay device against response to charging currents and comprising an asymmetric resistance; and a cycling relay associated With said service switch, and `functioning to neutralize the action of said service switch when the circuit is deenergized and restore its action when the circuit approaches full energization.

28. The combination defined in claim 27 in which the energy storing devices are electrostatic condensers.

29. The combination deiined in claim 27, in which the energy storing devices are electrostatic condensers and the asymmetric resistance devices are copper copper-oxide rectiers.

30. The combination dened in claim 27 in which the service switch grounds the electric circuit through a path established by the cycling relay when the latter is closed and such grounding serves to deenergize the winding of the relay.

3l. The combination ,of a pneumatic brake system having brake applying valves on the various vehicles of a train; two electromotive devices associated with the brake applying valve on each car and adapted to control the same to produce service and emergency applications; two electric operating circuits and a supervisory circuit extending throughout the train; manually operable controlling means at the head of the train for maintaining said operating circuits normally energized, and for deenergizing one or both at will; two means for storing electric energy on each vehicle charged respectively from said operating circuits; two relay devices on each vehicle, each responsive to deenergization of a respective operating circuit and arranged to discharge respective ones of said energy storing devices through corresponding ones of said electromotive devices to actuate the same; means comprising asymmetric resistance devices serving to protect said relays against response to charging currents; means at the rear of the train to energize the supervisory circuit from said operating circuits while said circuits are operative; and means at the front of the train and responsive to at least partial deenergization of the supervisory circuit to deenergize at least one of said operating circuits.

32. The combination of a pneumatic brake system comprising a brake pipe adapted to extend throughout a train, and brake valves connected therewith on the various vehicles of the train; normally deenergized electromotive devices for controlling at least one function of said brake valves irrespective of control exercised through the brake pipe; a normally energized electric circuit extending through the train; electric energy storing devices on the various vehicles, connected to be charged from said circuit; and means responsive to conditions in said circuit for discharging said energy storing means through said electromotive devices.

33. The combination of a pneumatic brake system comprising. a brake pipe adapted to extend throughout a train, and brake valves connected therewith on the Various vehicles of the train; normally deenergized electromotive devices for controlling at least one function of said brake valves irrespective of control exercised through the brake pipe; a normally energized electric circuit extending through the train; electric energy storing devices on the various vehicles, connected to be charged from said circuit; and means responsive to deenergization of said circuit for discharging said energy storing means through said electromotive devices.

34. The combination of a pneumatic brake system comprising a brake pipe adapted to extend throughout a train, and brake valves connected therewith on the various vehicles of the train; normally deenergized electromotive devices for controlling at least one function of said brake valves irrespective of control exercised through the brake pipe; a normally energized electric circuit extending through the train; electric energy storing devices on the various vehicles; connected to be charged from said circuit; means responsive to conditions in said circuit for discharging said energy storing means through said electromotive devices; and means comprising an asymmetric resistance device for limiting the charging ow to said storage device without materially limiting the discharging flow.

35. The combination of a pneumatic brake system comprising a brake pipe adapted to eX- tend throughout a train, and brake valves connected therewith on the various vehicles of the train; normally deenergized electromotive devices for controlling at least one function of said brake valves irrespective of control exer cised through the brake pipe; a normally energized electric circuit extending through the train; electric energy storing devices on the various vehicles, connected to be charged from said circuit; and means comprising a relay responsive to deenergization of said circuit and an associated asymmetric resistance for insuring slow charging of said storage device when the circuit is energized and rapid discharge of the storage device under` control of the relay through said electromotive device upon substantial deenergization of said circuit.

36. The combination of a pneumatic brake system comprising a brake pipe adapted to extend throughout a train, and brake valves connected therewith on the various vehicles of the train; three normally deenergized electromotive devices associated with each brake valve and each adapted to control a different function thereof irrespective of control exercised through the brake pipe; two normally energized electric circuits extending throughout the train; an electric energy storing device arranged to be charged from the first circuit and related to the first electromotive device; a second energy storing device arranged to be charged by the second circuit and related to the second electromotive device; a third energy storing device arranged to be charged from both circuits and related to the third electromotive device; means for deenergizing said circuits at will and for establishing a voltage difference between them while maintaining both energized; and means responsive to selective operation of the last-named means for discharging selected energy storing devices through their related electromotive devices.

37. The combination dened in claim 36, in which the means for discharging selected energy storing devices comprises relays.

38. The combination defined in claim 36, in which the means for discharging selected energy storing devices comprises relays and associated asymmetric resistance devices, said resistance devices serving to inhibit response of the relay to charging current while permitting relatively free discharge.

39. The combination defined in claim 36, in which the means for discharging selected energy storing devices comprises relays and associated asymmetric resistance devices, two of said resistance devices serving to limit the charging flow to the iirst and second energy storing devices to a rate insuilicient to cause response of the related relays, and the third of said resistance devices serving to protect one of said circuits against back flow from the third energy storing device.

40. The combination defined in claim 36, in which the discharge of the third energy storing device is eiiected by establishing a voltage diierence between the two lines while both are energized and the related electromotive device is maintained in an active condition by such voltage diierential after response to discharge of the related storing device.

41. A braking system comprising an electric energy storage device having a discharge voltage in excess of its charging voltage; means for charging said device; an electrically operated brake incapable of responding to the charging current but responsive to discharge of current from said energy storage device; and means for causing discharge of said device to actuate said brake.

42. A braking system for vehicles, said system comprising an electrostatic condenser; means for trickle-charging said condenser; a brake; electrical operating means for said brake; and means for causing discharge of said condenser through said electrical operating means to operate said brake. l

43. A braking system comprising a plurality of connected vehicles; electrically operated braking means on each of said vehicles; an electric energy storage device on each of said vehicles and connected with the braking means, said device having a discharge voltage in excess of its charging voltage; means for electrically charging said devices; and means for causing simultaneous discharge of the devices on each vehicle through their associated braking means to exercise a braking action on said vehicles.

44. A braking system comprising a plurality ot" connected vehicles; electrically operated braking means on each of said vehicles; an electrostatic condenser on each vehicle and connected to the braking means of the vehicle; means for charging said condensers; and means for causing simultaneous discharge of the condensers on all the vehicles to operate the braking means.

45. A braking system comprising a plurality of connected vehicles; electrically operated braking means on each of said vehicles; anv electrostatic condenser on each vehicle; means for trickle-charging said condensers; and means for causing discharge of said condensers through said braking means to operate the same.

46. A braking system comprising an electric energy storage device constructed to receive its energy by slow charge and to discharge its stored energy substantially instantaneously; means for charging said device; electrically responsive braking means incapable of responding to the charging current but responsive to discharge of current from said energy storage device; and means for causing discharge of said device to actuate said braking means.

47. A braking system comprising an electric.` energy storage device having an oscillatory discharge; means for charging said device; electrically responsive braking means incapable of responding to the charging current supplied to said device but responsive to the discharge current from said device; and means for causing discharge of said device to actuate said brake.

GEORGE V. MORRIS. 

